A variety of technologies are known for heating the constituents of glass to a homogenous molten state and maintaining glass in that state as it is being processed into products. Prominent among these technologies are inductive heating systems and methods. This is because the silicon that is present as silica in sand (the primary constituent of glass) is semi-conductive and therefore susceptible to electronic induction. Inductive furnaces may be used to initially melt the raw materials of glass into a liquefied state and inductive heaters may be used to heat the spinners that rotate at high velocity and centrifugally discharge multiple fibers of molten glass which are cooled and further processed into end products such as glass fiber insulation.
While effective for heating rotary glass spinners, currently available induction heaters produce waste heat that reduces their efficiency. In order to inductively heat a typical glass spinner, electrical power is consumed in the medium frequency (MF) rings of the heater. However, there is considerable additional conductive metal in the immediate vicinity of the MF rings and spinner including, without limitation, guard plates surrounding the MF rings.
During operation of the heater, this metal is also inductively heated, due to AC electromagnetic induction to establish electrical current in the metal, thereby resulting in consumption of electrical power. The power that is required to produce this waste heat reduces the efficiency of the heater and increases its cost of operation. These increased operational costs in turn increase the cost of the end products of the glass making process and reduce the profit that can be realized from their sale.
An advantage exists, therefore, for an energy-efficient inductive heater operable to heat a rotary glass fiber discharging spinner.